Safety switch



- May 17 1927.

A. E. GRISWOLD SAFETY SWITCH Filed Aug. 25, 1925 INVENTOR fiNDl-EEW :5". fi/swow TORNEY.

Patented May 17, 1927.

UNITED STATES ANDREW E. GRISWOLD, OF SEATTLE, WASHINGTON.

SAFETY swrrcn.

Application filed August 25, 1923. Serial No. 659,280.

My invention relates to improvements in safety switches and more particularly to switches for safety panel-boxes; it being one of the-objects of this invention to provide a double break switch having interchangeable line and load terminals.

Another object is to provide a switch of the above character embodying improved features of 'constrluttion in the means for mounting and mode of operating the movable switch parts between on and off position; and in the method of construction that provides cold fuses when the switch is off.

A still further object resides in the construction whereby contacts, fuses and switch parts are normally enclosed and' cannot be. exposed except when the switch is in off position. In accomplishing those and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein- F igure 1 is a vertical sectional view of. a safety switch embodying the present invention, the switch being shown in on position.

Figure 2 is a similar view, showing the switch in off position and the switch box door in open position.

Figure 3 is a horizontal section taken on thi? line 3-3 in Figure 2.

1 pane showing the arrangement of terminals and fuses.

Referring more in detail to the drawings- 1 designates the switch box, or houslng, wherein the switch terminals, fuses and switch mechanism proper, is contained. The box preferabl is of rectangular form and of sheet meta construction. It is provided at the front with an upwardly swinging, hingedly mounted door 2 which provides ac:

cess to the interior ofthe box for removing or replacing fuses. A lock, as indicated at 3, may be provided to hold the door closed. 4 des gnates the switch panel, which may be made of fibre, wood, or other insulating material and whlch is permanently and fixedly mounted on the back wall of the housing by means of two posts 5 and 6 that extend through the block and wall and which have nuts 7 and 8 threaded thereon to clamp rerespectivel against the inside of the panel and outsi e of the wall. These posts are re 4 is a front view of the switch located parallel to each other and in horizontal alinement. and serve, as will presently be described, as the mounting guides for the movable switch bar.

Secured in paired relation to the upper edge portion of the panel 4, by means of screws 10, are terminals 11-11, 12-12, 13-13, which have electrical connections respectively with switch jaws 14-14, 15-15 and 16-16. These switch jaws are vertically alined with corresponding sets of jaws 17-17', 18-18 and 19-19; the jaws 17, 18 and 19 being respectively connected electrically by means of conductive strips 20, 21 and 22 with fuse clips 23, 24 and 25.

These latter are arrangedv vertically below fuse clips 26, 27 and 28 that are respectivel connected by metal strips 29, 30 and 31 wit the switch jaws 14, 15' and 16'.- Corresponding upper and lower fuse clips are adapted to removably receive the ends of connecting fuses 34, 35 and 36.

Slidably mounted on the posts 5 and 6 is a horizontal switch blade carriage of novel construction which provides for quick and easy assembly or disassembly of parts and a rigid and durable construction. The carriage comprises spaced apart insulating bars 40 and 41 between which six switch blades, 42, are secured in vertical, edgewise posi tion, so that they may be moved with the.

carriage into and from the six pairs of switch jaws for the purpose of making and breaking connections through the terminals. The bars 40 and 41 are grooved transversely, as at 43 in Figure 3, toreceive the edges of the blades therein and are clamped against the blades by means of tubular bushings 45 that are extended through the bars and which have nuts 46 threaded onto their ends and tightened against the bars to clamp them tightly against the blades. The bush.- ings 45 are positioned properly to receive the mounting posts 5 and 6 therethrough and the carriage is adapted to be moved slidably on the posts to bring the ends of the blades into and from then respective switch jaws. When it is thought necessary, on account of the length of the insulating bars, additional clamping means is provided such as the connecting screws 44 which are extended through the bars near their outer ends.

The switch blade carriage is operated between on and 011' positions by means of a handle 50 that is pivotally supported at its lower end by means of a pin 52 that is carried by a bracket 53 on the outer side of the front Flute 54 that closes the upper front portion 0 the housing. This hand e' is connected pivotally, as at 55, with the outer end of a link 56 which, at its inner end, is pivotally fixed between wing plates- 57 attached to the bar 40. Inward movement of the handle moves the carriage to close the switch, and outward movement 0 ens it.

In order that-the parts inside 0 the housing cannot be reached except at times when the switch is open, I have rovided the handle with a leg v6O that exten s beyond the pivot point, and which is adapted, when the switch is closed, to engage with a stop lug 61 fixed to the outer face of the door 2.,

This leg retains the door closed while the switch i810. If it is desired to reach the interior of the housing for removing or replacing fuses, or for other reasons, it is first necessary to open the switch by movin the handle downwardly from position as shown in Figure 1 to that position shown in Figure 2, at which position the leg 60 is disengaged from stop 61 and the door is free to be opened.

With the switch so constructed, it is apparent that the terminals of each set may be used interchangeably and also that the fuses can be replaced or removed without danger for the reason that their terminals are cold at times when they can be reached.

Having thus described my invention, what I claim as new therein and desire to secure by Letters-Patent, is:

1. In a switch of the character described, the combination with a switch control member and fixed contacts of guide members, a carriage adjustable on the guide members by the control means and comprising spaced ington, this 1st day of Au apart bars, switch blades disposed between the-bars and adapted to be moved with the carriage from and a ainst the contacts, and means" connecting the bars and clamping them against the blades, holding the latter secure within the carriage.

2. In a switch of the character described, a mounting panel, switch jaws fixed on the panel, guide posts fixed on the panel, a switch control member, a switch blade carriage movable on the guide posts by'the said control member and com rising a pair of bars disposed in spac apart relation, switchblades disposed edgewise between the bars and adapted to be moved with the carriage into and from the jaws, tubular bushings extended through the bars and receiving the guide posts slidably therethrough and equipped at their ends with means for gagin the bars tightly clamped against the .a es.

3. In a switch of the character described,

a mounting panel, switch jaws fixed on the panel, guide posts fixed on the panel, a switch control member, a switch blade carriage movable on the guide posts by the said control member and comprising a pair of nonconductive bars disposed in parallel, spaced apart relation arid having transverse grooves in their adjacent surfaces, switch blades disposed edgewise between the bars and seated in 'said grooves and adapted to be moved with the carriage into and from the switch jaws, tubular bushings extended through the bars and receiving the guide posts slidably therethrough, nuts threaded on the ends of the bushings against the bars and clamping the latter against the blades.

Signed at Seattle, King County, Washst, 1923. ANDREW GRISWOLD. 

